doc: Clarify description of VALUES command

Greg Smith
Minor docs wordsmithing.

Swap the order of a couple of phrases to clarify what the adjective
"subsequent" applies to.

Joshua Tolley
Correct the documentation of pg_rewrite.ev_attr.

It claimed the value was always zero; it is really always -1.

Per report from Hari Babu
doc: Fix <synopsis> in <term> markup

Although the DTD technically allows this, the resulting HTML is invalid
because it puts block elements inside inline elements.  DocBook 5.0 also
doesn't allow it anymore, so it's fair to assume that this was never
really intended to work.  Replace <synopsis> with <literal>, which is
the markup used elsewhere in the documentation in similar cases.
Handle Unicode surrogate pairs correctly when processing JSON.

In 9.2, Unicode escape sequences are not analysed at all other than
to make sure that they are in the form \uXXXX. But in 9.3 many of the
new operators and functions try to turn JSON text values into text in
the server encoding, and this includes de-escaping Unicode escape
sequences. This processing had not taken into account the possibility
that this might contain a surrogate pair to designate a character
outside the BMP. That is now handled correctly.

This also enforces correct use of surrogate pairs, something that is not
done by the type's input routines. This fact is noted in the docs.
Don't downcase non-ascii identifier chars in multi-byte encodings.

Long-standing code has called tolower() on identifier character bytes
with the high bit set. This is clearly an error and produces junk output
when the encoding is multi-byte. This patch therefore restricts this
activity to cases where there is a character with the high bit set AND
the encoding is single-byte.

There have been numerous gripes about this, most recently from Martin
Schäfer.

Backpatch to all live releases.
Remove fixed limit on the number of concurrent AllocateFile() requests.

AllocateFile(), AllocateDir(), and some sister routines share a small array
for remembering requests, so that the files can be closed on transaction
failure.  Previously that array had a fixed size, MAX_ALLOCATED_DESCS (32).
While historically that had seemed sufficient, Steve Toutant pointed out
that this meant you couldn't scan more than 32 file_fdw foreign tables in
one query, because file_fdw depends on the COPY code which uses
AllocateFile().  There are probably other cases, or will be in the future,
where this nonconfigurable limit impedes users.

We can't completely remove any such limit, at least not without a lot of
work, since each such request requires a kernel file descriptor and most
platforms limit the number we can have.  (In principle we could
"virtualize" these descriptors, as fd.c already does for the main VFD pool,
but not without an additional layer of overhead and a lot of notational
impact on the calling code.)  But we can at least let the array size be
configurable.  Hence, change the code to allow up to max_safe_fds/2
allocated file requests.  On modern platforms this should allow several
hundred concurrent file_fdw scans, or more if one increases the value of
max_files_per_process.  To go much further than that, we'd need to do some
more work on the data structure, since the current code for closing
requests has potentially O(N^2) runtime; but it should still be all right
for request counts in this range.

Back-patch to 9.1 where contrib/file_fdw was introduced.
Remove ALTER DEFAULT PRIVILEGES' requirement of schema CREATE permissions.

Per discussion, this restriction isn't needed for any real security reason,
and it seems to confuse people more often than it helps them.  It could
also result in some database states being unrestorable.  So just drop it.

Back-patch to 9.0, where ALTER DEFAULT PRIVILEGES was introduced.
Remove unnecessary restrictions about RowExprs in transformAExprIn().

When the existing code here was written, it made sense to special-case
RowExprs because that was the only way that we could handle row comparisons
at all.  Now that we have record_eq() and arrays of composites, the generic
logic for "scalar" types will in fact work on RowExprs too, so there's no
reason to throw error for combinations of RowExprs and other ways of
forming composite values, nor to ignore the possibility of using a
ScalarArrayOpExpr.  But keep using the old logic when comparing two
RowExprs, for consistency with the main transformAExprOp() logic.  (This
allows some cases with not-quite-identical rowtypes to succeed, so we might
get push-back if we removed it.)  Per bug #8198 from Rafal Rzepecki.

Back-patch to all supported branches, since this works fine as far back as
8.4.

Rafal Rzepecki and Tom Lane
Tweak postgres_fdw regression test so autovacuum doesn't change results.

Autovacuum occurring while the test runs could allow some of the inserts to
go into recycled space, thus changing the output ordering of later queries.
While we could complicate those queries to force sorting of their output
rows, it doesn't seem like that would make the test better in any
meaningful way, and conceivably it could hide unexpected diffs.  Instead,
tweak the affected queries so that the inserted rows aren't updated by the
following UPDATE.  Per buildfarm.
Fix ordering of obj id for Rules and EventTriggers in pg_dump.

getSchemaData() must identify extension member objects and mark them
as not to be dumped. This must happen after reading all objects that can be
direct members of extensions, but before we begin to process table subsidiary
objects. Both rules and event triggers were wrong in this regard.

Backport rules portion of patch to 9.1 -- event triggers do not exist prior to 9.3.
Suggested fix by Tom Lane, initial complaint and patch by me.
Fix pg_isready to handle conninfo properly.

pg_isready displays the host name and the port number that it uses to connect
to the server. So far, pg_isready didn't use the conninfo specified in -d option
for calculating those host name and port number. This can lead to wrong display
to a user. This commit changes pg_isready so that it uses the conninfo for that
calculation.

Original patch by Phil Sorber, modified by me.
Add description that loread()/lowrite() are corresponding to
lo_read()/lo_write() in libpq to avoid confusion.
Fix cache flush hazard in cache_record_field_properties().

We need to increment the refcount on the composite type's cached tuple
descriptor while we do lookups of its column types.  Otherwise a cache
flush could occur and release the tuple descriptor before we're done with
it.  This fails reliably with -DCLOBBER_CACHE_ALWAYS, but the odds of a
failure in a production build seem rather low (since the pfree'd descriptor
typically wouldn't get scribbled on immediately).  That may explain the
lack of any previous reports.  Buildfarm issue noted by Christian Ullrich.

Back-patch to 9.1 where the bogus code was added.
Improve description of loread/lowrite.

Patch by me, reviewed by Tatsuo Ishii.
Fix unescaping of JSON Unicode escapes, especially for non-UTF8.

Per discussion  on -hackers. We treat Unicode escapes when unescaping
them similarly to the way we treat them in PostgreSQL string literals.
Escapes in the ASCII range are always accepted, no matter what the
database encoding. Escapes for higher code points are only processed in
UTF8 databases, and attempts to process them in other databases will
result in an error. \u0000 is never unescaped, since it would result in
an impermissible null byte.
Improve updatability checking for views and foreign tables.

Extend the FDW API (which we already changed for 9.3) so that an FDW can
report whether specific foreign tables are insertable/updatable/deletable.
The default assumption continues to be that they're updatable if the
relevant executor callback function is supplied by the FDW, but finer
granularity is now possible.  As a test case, add an "updatable" option to
contrib/postgres_fdw.

This patch also fixes the information_schema views, which previously did
not think that foreign tables were ever updatable, and fixes
view_is_auto_updatable() so that a view on a foreign table can be
auto-updatable.

initdb forced due to changes in information_schema views and the functions
they rely on.  This is a bit unfortunate to do post-beta1, but if we don't
change this now then we'll have another API break for FDWs when we do
change it.

Dean Rasheed, somewhat editorialized on by Tom Lane
Don't use ordinary NULL-terminated strings as Name datums.

Consumers are entitled to read the full 64 bytes pertaining to a Name;
using a shorter NULL-terminated string leads to reading beyond the end
its allocation; a SIGSEGV is possible.  Use the frequent idiom of
copying to a NameData on the stack.  New in 9.3, so no back-patch.
Observe array length in HaveVirtualXIDsDelayingChkpt().

Since commit f21bb9cfb5646e1793dcc9c0ea697bab99afa523, this function
ignores the caller-provided length and loops until it finds a
terminator, which GetVirtualXIDsDelayingChkpt() never adds.  Restore the
previous loop control logic.  In passing, revert the addition of an
unused variable by the same commit, presumably a debugging relic.
Don't pass oidvector by value.

Since the structure ends with a flexible array, doing so truncates any
vector having more than one element.  New in 9.3, so no back-patch.